Which gas accounts for about 1% of Earth's atmosphere?

Which gas accounts for about 1% of Earth's atmosphere?

• A. Nitrogen
• B. Argon
• C. Oxygen
• D. Carbon Dioxide

Answer: (B)

Atmosphere composition includes two major gases and several trace gases. Argon is one of those trace gases and is present in the air at about 0.9 to 1 percent by volume, making it roughly a one-percent component. It’s inert, a noble gas, and its amount comes from natural sources like the decay of potassium-40, so it stays in the atmosphere without reacting much. In contrast, nitrogen makes up about 78% and oxygen about 21%, which are far larger, and carbon dioxide is only around 0.04%, much less than 1%. So argon best fits the description of about 1% of Earth's atmosphere.

Atmosphere composition includes two major gases and several trace gases. Argon is one of those trace gases and is present in the air at about 0.9 to 1 percent by volume, making it roughly a one-percent component. It’s inert, a noble gas, and its amount comes from natural sources like the decay of potassium-40, so it stays in the atmosphere without reacting much. In contrast, nitrogen makes up about 78% and oxygen about 21%, which are far larger, and carbon dioxide is only around 0.04%, much less than 1%. So argon best fits the description of about 1% of Earth's atmosphere.